Gear lapping machine



Feb. 15, 1938. 'NYLAND 2,108,547

GEAR LAPPING MACH INE Filed Feb. 13, 1935 6 Sheets-Sheet 1 E. R. NYLAND2,108,547

GEAR LAPPING MACHINE Feb. 15, 1938.

Filed Feb. 13, 1935 6 Sheets-Sheet 2 Feb. 15, 1938.

E. R. NYLAND 2,108,547

GEAR LAPPING MACHINE Filed Feb. 13, 1935 6 Sheets-Sheet 4 A?! lid Feb.15, 1938. E. R. NYLAND mew GEAR LAPPING MACHINE Filed Feb. 13, 1935 6Sheets-Sheet 5 Feb. 15, ms.

rzawaraimL Patented Feb. 15, 1938 PATENT OFFlCE 2,108,547 GEAR LAPPINGMACHINE Edward R. Nyland, Detroit, Mich assignor to General MotorsCorporation, Detroit, Mich, a corporation of Delaware ApplicationFebruary 13, 1935, Serial No. 6,288

19 Claims.

This invention relates to a machine for smoothing up gear teeth by amethod known as lapping to. take ofi the high spots on the teeth and tomake all the teeth of a gear more nearly of identical configuration.

The heat treatment of gears after they have been cut causes differentamounts of warping throughout the length of the gear teeth which must betrued up, and it is the purpose of this invention to provide means toaccurately and speedily lap: the gears after heat treatment tomakeflthem all practically identical in configuration. r

My invention resides in the construction as described in thespecification, claimed in the claims and illustrated in the accompanyingdrawings, in which: i

Figure 1 is a side elevation of my machine as a whole.

I Figure 2 is an enlarged vertical section through the work holding headof the machine. 7

Figure 3 is a sectional view taken on the line 3--3 of Figure 2.

Figure 4 is an enlarged vertical section through the lap ring holdinghead.

Figure 5 is a side elevation of the oscillatory drive and brake for thelap: supporting sleeve, parts being broken away. 7

Figure 6 is a detail view of the brake adjusting means.

Figure 7 is a sectional view taken substantially on the line l'! ofFigure 4.

Figure 8 is a sectional View taken on the line 8- 8 of Figure 6. I

Figures 9 and 10 are enlarged vertical sections through the work holdinghead and a portion of the lap holding head, respectively, of a modifiedform of my invention. 7

Figure 11 is a top plan View of the driving mechanism shown in'Figure 10"illustrating its connection to the lap supporting housing.

Figure 12 is a detail View of an intermediate idler gear for preventingbacklash; and

Figures 13 and 14 are sectional views" taken on lines |3-l3 and l4-|4 ofFigure 12 respectively.

The machine comprises a base 2 having a hol low cylindrical standard 4secured in a vertical position on the base. Slidably supported on theupper end of the standard is the work supporting and driving headdesignated generally at 6. This head is composed of a short cylinder 8larger than the standard, in one side of which is rotatably secured agear, it which meshes with a rack I 2 vertically secured to the standard4. The shaft M on which the gear I0 is mounted projects through the sideof the cylinder 8 and may be turned to cause the cylinder to move up anddown 'on the standard for adjusting purposes. A rope I6 is secured toone side of the cylinder by a suitable clamp means l8 which rope runs upover a pulley secured to the top of the standard and is connected to aweight inside of the standard (not shown) which acts. as a counmrbalance for the weight of the head so that it may be moved up and downmore easily, 10

Supported on one side of the cylinder 8 by bracket 22 is a motor 24.Supported diametrically opposite is an irregular shaped casing 26 whichhouses the work holding and driving head. The casing supports ahorizontal worm: 28 driven by a pulleytfl which is in turn driven bybelt 32 from the motor 24. The casing 26 has a pair of verticallyaligned openings in the top and bottom which are surrounded byupstanding flanges 34 and 36, respectively. Within these 20 openings aresecured suitable flanged glands 38 and 40 respectively. An irregularhollow member 42 fits snugly within the glands 3B and 40 and has its:outer end secured by suitable clamp ing nuts 44. The central section ofthe member has a cylindrical opening 36 therein and the lower extremityhas a larger circular opening 48. Fitting snugly within the opening isis a solid stub shaft 52 in whose upper end is drilled and tapped a hole54. A bolt 56 extends through the center of the member 42 and isthreaded into the threaded opening 54 to secure the assembly together.

Rotatably mounted on the central enlarged portion of the hollow memberis a worm. wheel 58 which is driven by the worm 2a. Extending upwardfrom the top face of the'wheel 58 at diametrically spaced points are twolugs 60. An X-shaped member 62 keyed to the hollow member just above theenlarged lower portion forms a flexible driving unit with the wormwheel. The ends of a pair of the X arms 64 of the member are positionedon either side of the lugs 68. Springs 66 fitted in openings 68 in eachof the arms as abut the sides: of the lugs to which have a slightlycountersunk opening so the springs will not slip. The tension on thesprings may be adjusted by screws 10 which are finally held in callyopposite the motor is a casing 80 which is bolted to the cylinder I4.The vertical position of this casing may be adjusted by turning athreaded rod 82 which engages a lip 84 of the cylinder. Any horizontalrotation desired to bring the lapping ring into alignment with the workmay be made by loosening the clamp lever arm 8I and rotating the wholeassembly around standard 4.

In the top of the casing 80 is a circular opening 88 through whichprojects a vertical hollow sleeve 88, and which latter is supported by abearing 80 in the opening. The top of the sleeve projects above thecasing and has an inner circumferential notch in which is clamped thelapping ring 92 by a ring 94 and bolts 96. The sleeve is inwardly offsetbelow the bearing 80 and shoes 98 are mounted on the sleeve adjacentthis portion. Two diametrically opposite pins I00 extend through theshoes and are threaded on the outer ends. A yoke member I02 hasdiverging arms which engage these pins and are secured thereto by nutsI04. After engagement with the pins the arms then converge again untilthey meet on the other side of the sleeve where they are pivoted at I06to the casing. In the front end of the yoke member there is alongitudinal cylindrical opening I08 in which is slidably carried a pegIIO having a small hole I I2 at right angles to its axis. A stub shaftH4 is supported in an extension from the casing and has thereon at itsouter end drive pulleys I I6 which are driven from the motor I8 by beltII 8. From the inner end of the stub shaft projects a pin I20 eccentricto the axis of the shaft and which engages the hole H2 in the slidablepeg. It will be evident from this disclosure that as the shaft rotatesthe yoke will be moved vertically up and down, the side motion of thepeg I I0 being taken up by its relative motion within the opening I08.This action causes vertical reciprocation of the sleeve 88.

Pivotally connected to the lower portion of the yoke below the slidablepeg is a bolt I22 which extends through the casing and has a spring I28coaxially surrounding the outer end. The extremity of the bolt carries acircular disc I24 secured thereon by nuts I26 against which one end ofthe compression spring bears, the opposite end bearing against the outerface of the casing. The purpose of the spring is to bias thereciprocatory movement of the sleeve and yoke.

Below the shoes 98 is positioned a ring I30 on the outside surface ofthe sleeve adjacent which is a band of braking material I32. The loweredge of the latter is supported by a ring I34 clamped to the sleeve byset screws I36. Surrounding the circular band of brake material is abrake band I38 which also fits in between the rings I30 and I34. Theends of the brake band are bent outwardly to form short flanges andconnected together by a bolt I40 which passes through both flanges andhas a spring I42 surrounding the outer portion and bearing against oneflange and also against a washer I44 held on the bolt by a nut I46.

Integral with the brake band and positioned below the pivot I06 is anextending stud I48 upon which is rotatably placed a roller I50 andsecured thereon by a washer and nut I52. In the wall of the casing 80 inalignment with the stud I48 is a circular opening I54. A flangedcylinder I56 is projected through this opening and secured therein bybolts I58 which extend through holes I60 in the flanged portion. Theseholes I60 are not round but elongated so that the angular position ofthe cylinder may be varied. The inner end of the cylinder carries twodiametrically opposite arms I62 which contact the opposite sides of theroller and by varying the position of these arms the angularity of thebraking action may be varied for the vertical reciprocation.

Below the brake the sleeve 88 passes through a bearing I64 in the lowerpart of the casing 80 and has its lower extremity exteriorly threadedupon which a ball bearing supporting ring I66 is secured. A matchingannular member I68 acts to complete the race for the balls I70 and alsohas a rim portion which extends up around the lower extended part of thecasing. Springs I12 in this lower extended part bear against the annularmember and tend to keep the two apart, thus damping the oscillation ofthe sleeve. To the casing surrounding this latter assembly is secured athin cylinder I14 to protect the same.

Below the cylinder I'I4 on the standard 4 is a third supporting cylinderI16 whose distance from the base 2 is regulated by the screw thread I78.Pivoted to the lower corner is a waste pot I80 which may be swung toposition below the sleeve. Supported by the cylinder I'I6 above the potI80 is an angle bracket I82 which in turn supports a dished member I84below the sleeve and casing. The outer end of the bracket is formed intoa vertical circular hollow member I86 which extends up through anopening in the center of the dished member and then up through thecenter of the hollow sleeve. Slidable within this member I80 is asmaller member I88 within an opening in the lower end of which ispositioned a spring I90, the lower end of which bears against a plateI92 secured across the bottom of the opening in the member I86. A rodI04 extends through a central opening in the plate I92 and up throughthe center of the spring and is threaded into the member I88. The lowerexterior end of the rod has a Y-shaped yoke I96 thereon which receivesthe lever arm I98 pivoted to the side of the bracket at 260. A pin 202goes through the arms of the yoke and an elongated hole 204 in the leverto secure them together. The purpose of this structure is to move themember I88 up and down at will. A locking means to keep the member atany desired place is provided which consists of a rotary screw 206 thatcontracts the split casing I86 about the outer surface of the member I88and is operated by the lever 208.

The top of the member I88 is hollowed out and supports therein a shorthollow shaft 2I0 having an exterior flange 2| 2 at the top which engagesthe member I 88 and limits its movement into the same. The hollow shaft2I0 and the member I 88 are keyed together as at 2 I4. A stub shaft 2 I6having a pointed tip is positioned within the hollow shaft. Secured inthe top end of the hollow shaft is a roller bearing assembly 2I8 betweenthe hollow shaft and the stub shaft so that the latter may rotate freelytherein. A cap 220 is screwed onto the upper end of the hollow shaft toenclose the roller bearing. An inverted cup-shaped member 222 is securedon the stub shaft 2I6 to protect the roller bearing from foreign matterand extends down over the capped end. A second similar member 224 issecured to the upper end of the member I88 and extends down around theoutside of the hollow member I 86 to keep the foreign matter from thecontact surface between I86 and I83.

Between the pointed end of the stub shaft 2 I6 and the pointed end ofthe upper stub shaft 52 is carried a shaft 226 which carries the gear228 to impart vertical oscillations to the sleeve.

to be lapped. Rotary motion is imparted to the shaft from the upper stubshaft by a depending eccentric lug 235 which cooperates with "a clampedpiece 232 on the shaft to turn thelatter.

The operation of the machine will now be briefly described. The work andlap supporting heads are properly positioned upon the standard by movingthem up or down and then secured. The supporting cylinder I86 is thenpositioned on the standard so that the member I88 may be moved up toclamp the shaft 226. Shaft226 is then inserted within the sleeve havingits lower endresting on the end of the stub shaft 2 I 5. The shaft isthen swung into alignment with the upper stub shaft and the lever I98raised until it contacts the pointed end thereof, at'which time thelocking lever 258 is pulled up to lock the shaft in place. The shaft isfree to rotate upon these two pointed shaftsas it would be in a lathe,the depending lug 235 from the top stub shaft driving the same throughcontact with the clamp 232. When the shaft is in this position, the gearshould be opposite the lapping ring. The upper shaft is driven by themotor 24 at any desired speed through the belt 32, which drives a pulleydirectly connected to a worm 28. The worm drives a worm wheel having apair of upstanding lugs that impart rotary movement to an X-shapedmember through springs 66, the X-shaped member being connected to thestub shaft. In this manner the shaft is rotated at any desired speedthrough a resilient connection.

At the same time the sleeve 88 is reciprocated verticallyat a desiredrate by a second independent motor E8 through belt IIB, pulleys H6,shaft II and eccentric I28, which causes the yoke I52 The tension on thespring I28 is carried to any desired tension to pre-load thereciprocation of the sleeve to avoid roughness of operation atcertainspeeds. The sleeve is also mounted within the housin on springsI12 to damp the oscillations for the same purpoe. A brake I32, I38 isprovided to give a drag to the rotation to give friction necessary forlapping, and its action may angularly be adjusted by loosening bolts I58and turning the flange dependent upon the helical angle of the teeth.The tension of the brake may also be varied by the spring I 42.

In this manner when the machine is operating the teeth of the gear aresliding up and down on the teeth of the lapping ring and the gear isbeing rotated'to bring different teeth into engagement, and also to turnthe ring. Pressure is applied by the drag of the brake on the sleevewhich opposes the turning thereof. The teeth of the gear are less thanthe teeth of the lapping ring by an odd number so that the relativeposition of the work will be changed in relation to the lap. The speedsof the two motors may be relatively regulated to the proper ratio.

Since it is only essential in my machine to provide rotary motion andrelative reciprocation between the two members, my invention may becarried out as well by the modified form shown in Figures 9-14. In thismodified form the sleeve supporting the lapping ring is both rotatablydriven and vertically reciprocated, and the upper work supporting shaftmerely has the brake applied thereto to give the proper frictionalcontact.

In Figure 9 is shown the work holding head which is the same as in theprevious form, except that the teeth on the worm wheel have been removedand a brake -liningj234 inserted in the side ofthe wheel 236. Theresilient connection from the wheel to the central shaft is identical tothe former connection. A brake shoe 238 supported in any desired manneron the casing will give the desired braking force.

The rotary drive for the lap sleeve is shown in Figure 10. An externalring gear 240 is supported on and keyed to the sleeve 88 by a key 242 inplace of the brake lining of the previous disclosure. This ring gear iswide and has two parallel sets of helical teeth, 244 and 246, about itsperiphery, one of which is right-handed and the other left-handed, forlapping different gears. A supporting casing 248 for a driving geartrain has a portion fitting within the opening in the housing for thebrake adjusting yoke of the previous disclosure, which supports a doublegear 250 on a stub shaft 252 held in place'by set screw 253. One portion255 of gear 250 meshes with the ring gear 248. The other portion 256meshes with an idler gear 258 on shaft 260. This idler meshes in turnwith a wide faced gear 262 supported on shaft 284 on which shaft is alsosupported a worm wheel 266, which is driven from the pulley wheel 1 268outside the casing.

The casing 248 is pivotally supported on the housing 85 by an arm 21!)which engages a pivot pin 212 supported by a lug on the housing. In thismanner, it may be swung out from the housing, withdrawing the gear 250from engagement with the ring gear 245. Attached to the casing at apoint opposite to the arm 21B is a second arm 214 upon which ispivotally mounted a hook 216 by a pin 218. The hook has a handle 280integral therewith for turning the hook to desired positions. Secured tothe housing adjacent the position of the hook when the casing is innormal driving position is a pin 282 around which the point of the hookpasses to clamp the casing to the housing by pushing on the handle. Apiece of packing material 284 surrounds the opening in the housing andfits between the housing and casing to insure a tight joint,

In order to change the drive from the left-hand teeth to the right-hand,the handle 280 is moved clockwise, as seen in Figure 11, whichdisengages the hook from the pin and allows the casing 'to swing out.The set screw 253 is then loosened, allowing the shaft 252 to bewithdrawn and then gear 256 may be slid to the left from the casing.

A slotted latch 288 pivoted to the top of the casing is then swung outof engagement with the axial locking groove 2% of the shaft 259 and thelatter is pulled up by taking hold of the knurled end 263 until thegroove 265 is in position to be latched by the member 288, which isagain moved into place. The new pair of gears is then slid into thecase, the lower gear meshing with gear 245 and the upper with gear 258in its raised position. Shaft 255 is reinserted and set screw 253tightened. The face of gear 252 is'wide enough to remain in drivingcontact with gear 253 in either of its positions. The casing is thenswung to closed position and latched. Projecting from an opening in theforward portion of the casing adjacent the hook 215 is an adjustablestop pin 21! which engages the face of casing 80 and varies theengagement of the gear 250 with the gear 240 to adjust the backlash ofthe gears. The position of the pin is locked by set screw 213.

'To further reduce backlash in the gear train, the idler gear 253 ismade up of twothin gears 290 and 292 placed side by side and securedtogether by cap screws 294 as best shown in Figure 14.

The head and enlarged portion of the screw does not fit tightly with theopening in the gear 290,

so that a small amount of relative circumferential movement is possible.Between the screws, circular openings 296 are cut in the matching facesof the gears, half in the body of each gear in which are placed springs298. In opposite ends of the openings, plugs 300 are secured, one plugsecured to one gear and the other to the remaining gear, which will tendto cause relative rotation of the two in one direction and oppose therelative rotation in the opposite direction. This allows certainflexibility of engagement between the teeth of gears 250 and 258, andtends to keep them in contact without backlash.

It will be evident that if the sleeve be rotated in this manner and alsoreciprocated as before with the load on the teeth being regulated by thebrake in the work head, that the same lapping action will be given tothe teeth.

It is to be understood that while this invention has been described withthe internal ring gear referred to as the lapping member and theexternal or spur gear as the gear to be lapped, it is not intended tolimit the invention to this form and it would lie within the scope of myinvention to have the spur gear, the lapping member and the internalgear the member upon which it operates.

I claim:

1.. A gear lapping machine comprising, a base, a lapping ring supportedon the base, means for reciprocating the ring vertically, meanssupporting a gear having a smaller number of teeth in mesh inside thering, means for driving the gear and resilient means between the driveand the gear to absorb any uneven forces.

2. In a gear lapping machine, a support for a gear comprising arotatable shaft, a second shaft in alignment therewith having a drivingconnection to the first shaft, means on the second shaft to impartrotation thereto, a driving motor and resilient means between thedriving motor and said first mentioned means to impart rotation tothegear.

3. In a lapping machine, a sleeve for supporting a lapping ring, a yokemember pivotally connected to the sleeve, eccentric means connected tothe yoke member, means for driving the eccentric means to reciprocatethe sleeve vertically and spring biasing means connected to the yoke todampen the oscillations.

4. In a lapping machine, a sleeve for supporting a lapping ring, a yokemember pivotally connected to the sleeve, eccentric means connected tothe yoke member, means for driving the eccentric means to reciprocatethe sleeve vertically, a band of friction material secured to the sleeveand a brake band cooperating therewith to limit the motion of thesleeve.

5. In a lapping machine, a lapping ring, a sleeve for supporting thering, a yoke member pivotally connected to the sleeve, eccentric meansconnected to the yoke member, means to drive the eccentric means toreciprocate the sleeve vertically, a casing surrounding the sleeve, amember connected to the yoke and projecting through the casing and aspring to keep the member under tension to damp the vibrations of thesleeve.

6. In a lapping machine, a lapping ring, a sleeve for supporting thering, a movable yoke member pivoted to the sleeve to impart movementthereto, a friction band on the sleeve, a brake band cooperatingtherewith and means to adjust the angular resistivity of the brake bandin its action on the sleeve.

'7. In a lapping machine, a lapping ring, a sleeve supporting thelapping ring, means to reciprocate the sleeve vertically, braking meansfor the sleeve, and adjustable means for the braking means so that theangularity of its resistivity may be varied.

8. In a gear lapping machine, a lapping ring, means supporting thelapping ring, means to reciprocate the supporting means vertically,adjustable braking means for the supporting means, spring damping meansfor the supporting means, means for supporting a gear in mesh within thering and resilient means for driving the gear.

9. A gear lapping machine comprising, a lapping ring, a sleevesupporting said ring, a casing, spring biased means supporting saidsleeve on said casing, means for reciprocating said sleeve vertically,braking means on said sleeve, means for adjusting the angularresistivity of the braking means, means for supporting a gear in meshwithin the ring, a drive shaft for the gear sup port, an X-shaped memberon the shaft, a drive member supported by a second shaft having lugsthat fit between the arms of the X- shaped member, springs between thelugs and arms to form a resilient connection and drive means for thesecond shaft.

10. A gear lapping machine comprising, a lapping ring, a spring biasedrotatable sleeve supporting the ring, means for reciprocating the sleevevertically, a braking means for limiting the motion of the sleeve,supporting means for a gear inside the ring, driving means for thesupporting means including a resilient connection whereby as the gearrotates it will drive the ring and the reciprocation of the ring willlap the gear teeth.

11. A gear lapping machine, comprising a lapping ring having internalteeth, a sleeve supporting said ring, a casing, means to reciprocate thesleeve within the casing, resilient means between the sleeve and casingto dampen vibration caused by the reciprocation, means supporting a gearhaving a fewer number of teeth than the lapping ring in mesh therewith,the axis of the last mentioned means being parallel with the axis of thesleeve, means for rotating the gear and the ring together and brakingmeans to apply certain pressure between the teeth of the lapping ringand gear.

12. In a gear lapping machine, a lapping ring, a sleeve for supportingthe ring, means for rotating the sleeve, means for reciprocating thesleeve vertically, a casing around the sleeve, resilient means betweenthe sleeve and the casing, means supporting a gear within the ring whichis rotatable upon the teeth of the ring and braking means applied to thesupporting means to cause a given pressure between the teeth of the gearand those of the ring.

13. In a gear lapping machine, a sleeve for supporting a lapping ring,means for reciprocating said sleeve, damping means for the sleeve toprevent undue vibration, adjustable braking means for the sleeve, meanssupporting a gear within the ring, and means to rotate the gearincluding a resilient connection to absorb uneven drive.

14. In a gear lapping machine, a sleeve for supporting a lapping ring, acasing rotatably supporting the sleeve, means for rotating the sleevepivotally secured to the casing and comprising a gear train, one of thegears of which is composed of two parts relatively resiliently movableto reduce the backlash in the gear train.

15. In a gear lapping machine, a sleeve for sup- 7 porting a lappingring, a casing rotatably supporting the sleeve, means for rotating thesleeve secured to the casing comprising a gear train, said train havinga plurality of double gears so that the sleeve may be driven througheither one of two gears. l

16. In a gear lapping machine, a lapping ring, a sleeve supporting thering, a casing for support.- ing the sleeve, means for reciprocating thesleeve, means for rotating the sleeve pivotally connected on the casing,means rotatably supporting a gear in mesh with the ring, and brakingmeans to prevent free rotation of the gear when driven by the rmg.

1'7. A gear lapping machine comprising a lapping ring, means forreciprocating said lapping ring, means supporting a gear having asmaller number of teeth in mesh inside the ring, means for driving thegear and resilient means between the drive and gear to absorb any unevenforces.

18. In a gear lapping machine, means for supporting a lapping ring,means supporting a gear having a smaller number of teeth in mesh insidethe ring, means for rotating one of said means to thereby rotate theother including a resilient member to absorb any uneven forces and meansto reciprocate said gear with respect to said lapping ring.

19. In a gear lapping machine, means to support a lapping ring, means tosupport a gear to be lapped having a fewer number of teeth in meshwithin the ring, means to reciprocate one of said means with respect tothe other, driving means to turn the gear and ring including a resilientmember to absorb any uneven forces and braking means to limit rotarymovement of the lapping ring with respect to said gear.

EDWARD R. NYLAND.

